Remove Duplicates & Customize the “Open With” Menu in Mac OS X

Open up Terminal and enter the following two commands, each followed by the Enter key. These commands will rebuild the LaunchServices file and will refresh the Finder so that the changes take effect. You might have to wait a minute or two for the first command before killing the Finder, as the database needs time to restructure itself.

/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

killall Finder

All of the duplicates that previously appeared in “Open With” should now be gone. If you’re not comfortable using Terminal, try out the next method.

OR Use OnyX to Do It for You